def count_use_for(n=10):
    result = []
    for x in range(n):
        result.append(x)
    return result


def count_use_while(n=10):
    result = []
    while n > 0:
        n -= 1
        result.append(n)
    return result


print(count_use_while(15))
print(count_use_for(20))